This invention relates to an adjustable foundation piering system and more particularly to such a system which is an improvement over the foundation supports for building and the like.
In building construction on expansive soils such as bentonite, foundations are generally built on concrete piers which according to the engineering specifications should eliminate building foundation movement over time. However this is a fallacy and the foundations are required to be re-leveled as ground movement occurs. These soils cause substantial damage to home and buildings and require expensive re-work to them. In an effort to eliminate this movement of the soil many different actions are taken. Such actions include engineered concrete piers reinforced with steel rebar which are drilled to substantial depth and in some cases to depths of up to twenty feet. Once the pier is drilled and the reinforcing rebar is added, concrete is poured into the void and must set for at least seven (7) days before additional work can be performed after the seven (7) days, the foundation can be poured with attachments to the piers. After the building is complete, non-expansive soils are placed around the foundation which has necessitated the removal of the expansive soils from the area around the foundation to reduce the amount of heaving as much as possible. When the expansive soils are encountered the entire foundation rests on the piers with void material between the ground and the base of the foundation in between each pier.
Unfortunately, all of the processes used only reduce the problem encountered with expansive soils and in time the foundation shifts as a result of the expansive soil. Where caissons with rebar have been used, the soil must be removed and the rebar must be cut that is embedded into the foundation so that the foundation can be re-leveled, and in most cases requiring a portion of the foundation to be raised. There are numerous devices utilized to re-level the foundation including piering devices. The problem is that these devices require a substantial amount of work and monies. There is a piling system of Gregory, U.S. Pat. No. 4,754,588 which attempts to eliminate the problem with soils having various compaction. This system is extremely intricate and ties the pier to the foundation with an extensive amount of steel bars extending through the sleeve. The disadvantage of this system is again obvious as when there is movement of the foundation due to expansive soils, the piling system of Gregory will require the extensive shoring of the foundation that has been a problem with the concrete piers as well.
Nally, U.S. Pat. No. 5,123,209 shows a method of re-leveling a foundation after movement has occurred.
Gregory, U.S. Pat. No. 4,695,203, shows a method of shoring building's relating to the problems set forth earlier.
In Langenbach, Jr., U.S. Pat. No. 3,902,326, it is disclosed the use of a piling member which is capable of being driven into bedrock sufficient to shore a foundation. It utilized a hydraulic pump and attachment to the foundation as a means of shoring up the foundation as shown similarly in Ortez, Freeman, III, Rippe, and McCown, U.S. Pat. Nos., 5,492,437, 5,433,556, 5,234,287, and 5,154,539, respectively. Although, there are many methods of attempting to shore up a foundation including those discussed above, none provide a stabilization system that allows for correction after the devices have been installed.